Paddle for impact type of pulverizers



y 1929- w. w. PETTIB ONE 1,711,964

131mm,; FOR IMPACT TYPE OF PULVERIZERS Filed July 5, 1927 2 Sheets-Sheet1 Inventor Peizibane A tlorney May. 7, 1929. w. w. PETTIBONE .PADDLE FORIMPACT TYPE OF PULVERIZERS Filed July 5, 1927 2 Sheets-Sheet 2 InventorW WPet bone Attorney Patented May 7, 1929.

UNITED STATES PATENT OFFICE- WALTER w. rn'r'rrnonn, or BIRMINGHAM,:ALABAMAQASSIGNORVTOV rm. EFFICIENCY ENGINEERING CGRIPORATION. Aoonron-A'rion; or ALABAMA.

PADIDLE ron IMPACT TYPE orr'u rlvnniznns.

Application filed .Tuly 5,

My invention relates to a new and improved type of paddle impact type ofpulverizers adapted for pulverizing coal, minerals, or chemicals, andrelates to that class of pulverizers in which the material to be treatedis passed successively through the desired number of stages in eacho'fwhich it is subjected to an impact action by the rotating paddles,the liners, and theengag'ement of oneparticle against other particlesunder treatment.

Heretofore, in pulveri'zers of the type in question it has been thecustom to mount the paddles upon the disk or other rotor by means of apin or pins which intersected the base of the paddle and which wererequired to withstand the centrifugal strain on the paddle.

The object of my present invention. is to so design thepaddles and therotor disk'upon which they are mounted that it is unnecessary to weakenthe base of the paddle with a hole for a securing pin and in which thepin will co-act with a pair of shoulders on the paddle base so as tohold the paddle engaged in a non-radiaLslot in the periphery of thecarrying disk. Asa result of this construction the paddle can be mountedvery simply and yet with great strength and firmness on the disk and canbe removed with great ease. I

My invention further comprises the novel details of construction andarrangements of parts which,in their preferred embodiment only, areillustrated in the accompanying 5 drawings which form a part of thisspecification, and'in which z- 1 Fig. 1 is a view illustrating insideelevation a typical impact pulverizer ofthe two stage type having thecasing broken away to show the fan and two of the rotor disks invertical cross-s'ection, the paddles mounted on the disks being shown infront elevation.

Fig. 2 is an enlarged detail viewin side elevation of one of the paddlesshown mounted on a fragment of the rotor disk.

Fig. 3 is a cross-sectional view taken on the line III-III of Fig. 2showing the paddle in rear elevation. Similar reference numeralsreier'to similar parts throughout the drawings.

In the embodiment of my invention illus- 1927. SerialNo. 203,642.

trated, I have chosen for purposes of illustration, the type of iinpactpulverizer as especially adaptedfor the pulverizing ofcoal,

in which 4 indicatesa suitable feed mecha msm by means of which the coalis fed at a uniform rate into the initial treatment chamher 5, whereinis mounted a disk'dfast on a shaft 7 driven through a coupling 8 fromthe shaft 9 of a motor 10.. The shaft 7 turns in suitable bearings 11and '12 in the-end walls 13 and 14. respectively, or thepulverizercasing. In the form shown, 'as'econd disk 6 is shown mounted in thesecond treatment chamber 5 both chambers being cylindrlcal in type-andthe chamber 5 oi greater diameter than the chamber 5. The chambers i 5and 5 are separated by a diaphragm 15 suitably mounted in the casingandproject ing inwardly from the peripheral wall ofthe chamber 5 adistance which brings its inner periphery wall within the peripheryof-the disk 6. The disk 6 is made ofa larger diameter than the disk 6 tocorrespond with th e increased diameter ofthe chamber 5, and a diaphragm15 defines the opening from the chamber 5 -into an air chamber 16, whichhas an annular valve 17 therein controlling a plurality of ports 18 andthereby regulat ing the volume of air admitted at this point. Thediaphragm 15 is preferably designed so that its inner periphery standsat a greater distance from the shaft 7 than that of the diaphragm 15,but the diameter of cutter opening in diaphragm 15 is substantially lessthan the diameter of the disk 6. 'I The air chamber on its other sidefrom the diaphragm 15 is'provided with an annular diaphragm wall 19, theinner periphery of which lies closer to the shaft than the innerperiphery of the diaphragm 15 and leaves an annular outlet through whichthe treated products are borne on an air currentinto the fan chamberfrom which they are blown out by the fan 20 through the outletconnection 21 toany desired point of use.

" While I have defined structurally a suit-V able apparatus for theembodiment of my invention, it is nevertheless to be understood thatthat described presents merely the'suitable embodiment for itsuse and.may be va ried according to the material to be treated and the outputdesired and therefore may operate with a single stage or multiplestages.

My present invention is more particularly concerned with theconstruction of the paddles 22 which are suitably mounted on the r0- tordisks 6 and 6, and by reference to Figs. 2 and 3 the detail constructionof these paddles and the preferred manner of mounting them on the diskswill be better understood. In Fig. 2 it will be observed that the disk 6is provided with a slot 23 projecting i11- wardly from its periphery atan acute angle in a radial line, this angle being preferably in thedirection of the rotation of the disk, and the slot is also preferablyof equal width throughout its length. An intermediate point of theunderlying edge of the slot is intersected by an annular bnre or drillhole formed in the disk for the reception of a paddle lock pin 24,whichhole will lie preferably tangent to the edge of the slot. It ofcourse will be understood that pins of different shape can be used, butthe round pin shown is preferred. The pin is designed to projectsubstantially on each side of the disk so as to engage the grooved outerends of lugs 25 that project rearwardly from the base 26 of the paddle22. This base is wider than the slot and at its intermediate portion iscut away and reduced to provide a web 27 shown in dotted lines Fig. 2,which will fit loosely in the slot 23 in the disk while the sides of thebase will straddle the disk with a snug fit on each side, and the pin 24will project substantially beyond the sides of the shoulders 25 toreceive a cotter pin 28 in each end by means of which it is demountablyheld in operating position. Preferably, the web 27 stops short of theend of the base so that the latter will overlap the disk below thebottom of the slot, as appears more clearly in Fig. 3. Also, the frontface of the paddle opposite the reduced web 27 is sloped inwardly at 29to facilitate the casting or forging of the paddle with the design ofthe base described. It will be noted that the working or front surfaceof the paddle extends down below the periphery of the disk and isradially disposed and therefore at an acute angle to its base. Theadvantage of so constructing and mounting the paddle base lies in thefact that in operation the action of centrifugal forces will bedistributed from the base to the slot walls of the disk and, through theshoulders 25, to the pin, and the latter will hold the paddle with itsfull shearing strength interlocked with the disk. The paddle will,therefore, not be weakened by reason of holes for any attaching pins orbolts, nor does the lock pin take the entire centrifugal strain on thepaddle. There is another particular advantage arising from my manner ofmounting the paddles, which is that I avoid the difliculty of accuratealign ment of the holes in the paddle base and disk, which hasheretofore been necessary, as in my construction the paddles will fitloosely in the slots 23 and will set themselves in working position whensubjected to centrifugal force.

In Fig. 2 I have shown a somewhat exaggerated clearance between the web27 of the paddle base and the forward edge of the slot 23 and I have notsought to show the paddle in the exact position that it will assume atwork, it being contemplated that the paddle will rock further rearwardand its base will rock forward and take a bearing against the inner endof the forward edge of the slot and against any suitable point either onthe pin or rear edge of the slot.

Having mounted the paddles in the manner described, the operation of thepulverizer is that well understood by those skilled in the art, the fuelbeing carried through by an air draft and submitted to the action of thepulverizer impact rotors in the one or more stages employed and passingout with the air current to the point of use.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is

1. In a pulverizer, a rotor disk having a plurality of paddle mountingslots inclined to a radial line, paddles having bases adapted to enterthe slots, a lock element for-each paddle, and a lock shouldercomprising a lug formed on each paddle base extending alongside the diskand adapted to be engaged by its said'respective lock element to holdthe paddle base in its respective slot.

2. A pulverizer. according to claim 1, in which the slots are inclinedforwardly relative to a radial line- 3. Av pulverizer according to claim1, in which the lock shoulder is formed on the rear face of the base ofeach paddle.

4. A pulverizer according to claim 1, in which the lock element is anaxially extending pin mounted in the rotor adjacent to each paddle base.

5. In a pulverizer, a rotor disk having a plurality of non-radialperipheral slots, paddles having bases adapted to fit loosely in saidslots and having rearwardly projecting lugs which straddle the disk, anddemountable lock pins mounted in the disk and each adapted to engage thelugs of its respective paddle to lock same on the disk.

6. In a pulverizer, a rotor disk having a plurality of non-radialperipheral slots, paddles having bases reduced along their centers tofit loosely in said slots and to provide portions overhanging the frontand rear edges of said slots, and locking pins adapted to engage therearwardly projecting portions of the bases to lock them in position intheir respective slots.

7. A pulverizer according to claim 6, in bases, and a demountable lockelement on the which the paddle bases overlap the base of the rotoradapted to engage the lock shoulders slots. of each paddle and hold somein the slot, the 10 8. In a pulverizer, a rotor having a plupaddle basebeing wide enough to overlap the rality of non-radia1 slots, paddleshaving lock element.

bases adapted to be received in the slots, reztr- In testimony whereof Iaffix my signature. wvardly disposed lock shoulders on the paddle WALTERWV. PETTIBONE.

